Centrifuge Modeling of Vessel Impact on Bridge Fender Systems

Abstract

Bridge or berthing structures are susceptible to accidental ship impacts that may pose a hazard to human life, property, and the environment. Therefore, fenders are often constructed around bridge piers for protection. Although efforts have been made to estimate the ship impact load, understanding of the mechanism of ship impacts on bridge fender systems is still inadequate due to insufficient experimental evidence. In this study, a comprehensive centrifuge model test program involving 60 ship impact tests was performed on a 3×3 pile group to systematically examine the effect of fender systems on a bridge pile foundation subjected to ship impacts. Two types of fenders with different stiffnesses, as well as a benchmark test without fenders, were investigated under different vessel tonnage and impact velocity values. Based on the test results, the characteristics of the impact loads were analyzed. The energy transfer patterns with and without fender systems were compared. The influences of the ship tonnage, impact velocity, ship bow structure, and bridge superstructure mass on the impact load with different fender systems were studied. Finally, empirical equations are established to relate the ship impact load with key influencing factors regarding the fender system, the ship, and the bridge.